Carburetor



Nov., 10, l93l w. c. CARTER 1,831,439..

CARBURETOR I Filed 001;. 17, 1927 Patented Nov. 10, 1.9.31

n winmix a camina, orrm'r, anoniem OFI-*ica GABBURETOB applicati@ ma amber iv, im. semi no; saam.

This invention relatesfto carburetor. b 1 One object of the invention is to provide a carburetor that is equipped with an adjustable fuel supplying device for delivering fuel L tothe main passageway of the carburetor at y a point in proximityv to the throttle valve when said valve is closed or only partly open. Another object is to provide a carburetor that is equipped with a' choking device of 10 novel construction.

Another object is'toprovide a carburetor that is equipped with a by-pass around the a throttle valve, and also equipped with a choking device which is combined with said bypass in sucha way that saidby-pass will automatically come into. -service while the choking device lis moving towards itsclosed position.

Andsti/ll another object of the invention 29 is to provide a carburetor which is of such a construction that the act of moving the choking deviceinto its closed or partly closed position automatically increasesthe idle speed of the engine without affecting the throttle valve or the device that is used to determine the idle positioniof the throttle valve.l Other objects anddesirable features of my invention will behereinafter pointed out.

I have herein illustrated my present invention embodied in a carburetor of the neral type illustrated in my pending application f #1927, butI wish it to be understood thatI my present linvention is applicable to varlous 351 other types and kindsjof carburetors..

. Figure 1 of the drawings is atop plan view of a carburetor embodying my present invention.

Figure 2 is a vertical sectional view of said o carburetor, taken on the line 2-2 of F-igure 1. Fi re 3 is a viewsimilar 4to Fi re 2, showing the choking device moved into its partly closed position. o 'l Figure 4 is an enlarged detail view of the means that is used to adjust the fuel tube .which constitutes the. fuel duct through which fuel is conveyed from the accelerating well to the intake ,above the throttle valve f when the throttle valve is; closed or only partly open. ,IE' v -around the throttle valve that comes from the spirit of my invention. It isherein Figure 5 is a detail view, illustrating the means that is used to actuate or adjust the choking device; and i Figure 6 is a detailview, taken on the line 6--6 of Figure 3, illustrating the by-pass into -service when the choking device is movedtowards its closed position.

Referring to the drawings which illustrate the preferred form of my invention, A designates the body casting of the carburetor which is provided with a straight, verticallydisposed ore 1 that constitutes the main passageway .of the carburetor, 2 designates a throttle valve which is arranged in said main passageway adjacent the upper end of saine, 3 designates an air chamber which communicates with the lower end of the main passageway, 4 desi ates a depending cylindrical portion on t e body casting that serves as a guide for an annular float `5 in the bowl 6 that constitutes the float chamber of the carburetor2 7- designates an accelerating well or reservoir in the dependingportion 4 on the body castin inside of which is arranged a 75 vertically-disposed tubular member 8 thatprojects upwardly towards the main passageway 1 in concentric relation with the same and terminates preferably inside of a Venturi member 9 that is arranged inside o f the main passageway 1 below the throttle valve, and 10 fon patent Serial No. 206,028, filed July 1li,i d

esi nates a vertically-disposed fuel supplying evice mounted in the bodylcasting A in suchaf manner t at it forms part of a fuel duct or pasageway through which fuel is conveyed from the accelerating well 7 to the main assageway 1 at apoint above the throttle va ve 2 when said throttle valve is closed or only partly open, and through which fuel is conveyed to a b -pass around the throttle valve when the cho ing device of the carburetor is in its partly closed position. The lower -pgrtion of the fuel Aduct just referred to can formed in various wayswithout departing 95 illustrated as being formed by a verticallydisposed groove or bore 11 in the dependin rtion 4 of the body casting, arranged wit itsA lower end communicating with the bottom or lower end of .the accelerating well -7 and with its upper end communicating with a` fuel duct 12 formed in a lug 13 on the body casting that receives the lower end portion 4of the adjustable fuel supplying device 10, previously referred to, which is herein represented as consisting of a tube. Communication between the fuel tube 10 and the fuel duct 11 just referred to is established 'by means of a fuel orifice 14 in a plug 15 that is removably mounted in the body casting A, as shown in Figure 2, it being preferable to construct the carburetor in this manner, so as to permit the use of an orifice 14 of a definitev size that forms part of the passageway through which liquid fuel is conveyed from the accelerating well 7 to the main passageway 1 above the throttle valve and which can be cleaned easil in the event it becomes stopped up, simply y removing the plug 15 and cleaning the orifice 14in same. Air is admitted from the air chamber -3 to the lower end of the fuel passageway in the fuel supplying device 10, preferably by an air port 16 that is formed in the lug 13. The upper end portion of the fuel supplying device 10 is so formed that when the throttle valve 2 is closed or'only partly open, fuel will pass `from the upper end of said device into the main passageway 1 at a point above the throttle valve and air will also enter the fuel passageway of said device 10 from the main passageway 1 at a point below the throttle valve', and thus cut down or reduce the suction that isexerted on the upper end of said device 10 by the highyacuum which then exists in the intake of the engine. When the throttle valve is moved forwardly away from its idle position the admission of air to the` upper end of the fuel passageway of the device 'I0 is cut off, thereby causing the full force of the vacuum which then exists in the intake of the engine to be exerted on` a fuel, discharge port or equivalent means located at the upper end of the tube or device 1 0. In the carburetor herein illustrated the fuel tube 10 is closed at its upper .end and is provided at a point below said closed upper end with a lateral fuel discharge port 10a arranged so that when the throttle valve is in its closed positlon, as shown in Figures 1, 2 and 3, said discharge port 10a will be positioned in closeproximity to the throttle valve, usually with the top` halfof said=p0rt projecting above/the throttle valve. l A t a point below said lateral fuel discharge port 10a are one or more air-inlet ports 10b which are located below the throttle valve c when said valve is in its closed position.

The means that is used to admit fuel from the float chamber to the accelerating well 7 can be constructed in 'various ways without departing from the spirit of .my invention.

1n the carburetor herein /illustrated an or-I ifice 17 of a definite sizecis provided for 'admitting fuel from the float chamber to a relcommunication with the accelerating wellv 7 and which virtually forms the bottom or 'lower end -portion of said accelerating well,

communication being established between the accelerating well 7 and the shallow chamber.

municates with the chamber 7, as shown in Figure 2, and as said chamber 7"1 isrelatively shallow. surging of the liquid fuel away from the liquid end of the fuel duct 11 is effectively prevented at times when the accelerating reservoir contains only a small quantity of fuel. The tubular member 8, previously referredto, that projects upwardly through the accelerating well 7 is. provided at its lower end with a main liquid fuel supply device which may either consist of a fuel orifice 19, as'shown in Figure 2,.` or a fuel nozzle that dischar es upwardly into the accelerating well. member 8 is providedat its lower end, with one or a plurality of vertically-disposed slots 2.0. that project upwardly from the bottom of the accelerating well and which are of such length that th'eir upper ends terminate above the normal level of the fuel in the float j bowl, represented by the dot anddashdine in'F-igure 2. f

When the engine is idling with the throttlervalve 2 in its closed position, liqud f uel with air will be drawn upwardly through the tube or fuel supplying device 10 anddischarged from the upper end of same into the main lpassageway 1 at a point abovethe throttle valve, due to the fact that the vacuum in the intake of the engine'produces a suction in the fuel passageway of the device 10 that inthe fuel passageway in thedevice 10, be-

cause ,air is entering the 'lower end ofvsaid fuel passageway from the air chamber f3 through the air port 16 and air is also entering the upper end portion of the fuel passageway in the device 10 through one or more air inlets 10'J in same which at this time are located below the throttle valve. After 'the throttle valve has been moved into such a position that the air inlets or openings 10"/ in the upper endI portion of the device 10 willbe positioned above the throttle valve` the high vacuum which 'exists in the intake of the engine when the throttle valve is partopen will become operative for drawing the uel upwardly Athrough the fuel passageway of the device -10,'thus increasi the amount of fuel which said device intrlbuces into the passageway 1. After the throttle valve has reached such a position that the device 10 ceases to supply fuel to the main passageway l the air that is drawn upwardly into sald passageway through the annular the wellv 7 and into the vertically-disposed` slots 20 in the member 8, and thereafter upwardly through said member 8, thus causing more or less of the fuel in the accelerating well 7 to be labsorbed by the air and carried upwardly into the main passageway 1.

. When the throttle valve Areaches such a position as to canse suicient air to travel through the well 7 to keep said well dry,

f or practically so, the suction inside ofthe tubular member Stbecomes strong enough to cause fuel to be drawn from the main hquid tated, so as to raise or lower the tube 10, and thus accurately adjust the fuel dischargek fuel supply orifice 19 and carried upwardly through the tubular member 8 into the main passageway l. Whenever the throttle valve is moved from its high speed position towards its closed or partly open position, the liquid fuel builds up in the accelerating well 7, so as to form an accelerating charge that is in readiness to be carried into the main passageway 1 by the air that rushes downwardly through said well, and thence upwardly through the tubular member 8, if the throttle' valve is opened suddenly.

One of the novel features of my present invention consists in constructing the fuel supplying device`l0 in such fa way that it can be adjusted easily so as to accurately'position the fuel discharge orifice 10 at the upper end of same with relation to the throttle valve 2f( when the carburetor is being installed on'the engine on which it is used. Various means can be used to adjust the fuel discharge port 1()a of thedevice 10 with relation to thethrottle valve, but I prefer to form the` device 10 from a tube mounted in the body castin 4 A of the carburetor in such a way that said tube can be raised or lowered,

and provide a means 21 for adjusting said tube vertically, themeans 21herein villustrated consisting of a rotatable plu mou-nted in the body casting A at one si e of the tube 10 and provided at its inner end with an eccentricall -disp'osed, arc-shaped rib 22,

as shown in Figure 4, that enters a notch or groove in one side of the tube 10. The plug 21 is provided in its puter end with a knurled nger piece 23 by which said plug can be roorifice 10a and the air inlets 10b at the upper end ofsaid tube with relation to the throttle valve 2, thereby simplifying the .manufacnother novel feature of my present invention consists -in arranging acup-shaped member 24 in opposed relation with the contracted end of the Venturi 'member 9 and mountingone of said members in such amanner that -it can be moved towards and away from the other so as to reduce the admission of air to the main passageway 1 of the carburetor below the throttle valve, thus forming a choking device that is intended to be `used-to facilitate the starting of the engine when it is cold. Preferably, the ,Venturimember 9 is reciprocatingly mounted in the .body casting A ofthe carburetor at a point above the cup-shaped member 24 which can be conveniently mounted on the tubular member 8, said cup-shaped member having a rim 24aagainst which the lower endof the Venturi member 9 strikes when said Venturi member is moved downwardly into its closedposition so as to chokethe carburetor. .By making the stationary member 24 of the choking device cup-shaped instead of in the form of a continuous flat surface, towards which the movable member 9 of the choking device is moved to choke the carburetor, I am able to materially reduce the stroke or degree of reciprocating movement of said member 9, thereby making the carburetor-more compact. Inother words, the cavity or depression in the -cup-shaped member- 24 increases the area of the air passageway through which the air circulates after entering the space between the rim' of the cup-shaped member 24 andthe lower end of the Venturi member 9 sulicient-ly to make it practicable to ar'- range the lower end of the Venturi member comparatively close to the rim 241 of the cuplshaped member when said Venturi member z 1s 1n its normal position shown in .Figure Awhich the air circulates after flowing inwardly between the two opposed members of the choking device. Any suitable means can be used tomove the Venturi member 9 to wards and away from the cup-shaped member 24, the means herein illustrated for this purpose consisting of a rotatable device 25, mounted in the body casting of the carburetor, and provided at its inner end with an eccentrically-disposed pin or projection 26 that enters a hole in the side of the Venturi member 9. When the device 25 is rotated in one direction, the Venturi member 9 will move downwardly, and when said device is rotated in the opposite direction, the Venturi member will move upwardly. The device 25 is provided at its outer end with a lever 27 for turning the same and a torsion spring 28 is combined with said device 25 so ik as to normally exert pressure on same in a direction to -hold the Venturi member, constituting the choking device of the carburetor, in its open or inactive position, as shown in Figure 2.

' Another' novel'feature of my `present invention consists of a carburetor constructed in such a manner that the act of moving the choking device into its closed or partly closed position automatically increases the idle speed of the engine without affecting the throttle valve or the device thatis used y to determi-ne the idle position of the throttle valve. l

In such a carburetor the increased speed of the engine above its normal idle speed, produced by closing the chokingdevice, indicates to the operator in charge of the engine that the choking device should beopened or restored to its normal open position in the event the operator has failed to do this after the engine has warmed up, thereby effectively preventing numerous troubles that result from operating an internal combustion en- `gine with too rich a mixture, as well as tending to conserve on the consumption of fuel.v

The 'above described highly desirable result can be" attained in Various ways Without departing from the spirit of my invention but I prefer to construct the carburetor in such a manner that the act of closing a choking device, of any preferred type, increases the flow or delivery of fuel from a fuel supplying device and also automatically brings into service a throttling by-pass around the4 throttle valve, which establishes communica- Ation betweenthe portions of the main passageway l, located above and below the throttle valve 2. Likewise, the act of opening said choking device automatically renders inoperative the throttling by-pass above referred to. i

The carburetor herein illustrated, which 'e represents rthe preferred form of my invention. is equipped with a by-pass around rthe throttle valve that comes into service auto.-

matically when the choking device starts to move towards its closedposition, and means is provided for automatically increasing'the suction on the fuel supplying device 14 when the choking device starts to move towards its 'closed'positiolr vVhen th choking device is in its fully closed position he by-pass around the throttle valve permits a-rich combustible f-enginaandthus facilitates easy starting of mixture" to flow freely into the intake of the in charge of the engine to set the choking `de vice in such a position that the idle'speed lof the engine will 4be high enough to eliminate the possibility of the engine stopping if the operator retards the throttle valve when the engine is cold. So far as this feature of my invention is concerned, it is immaterial what type or kind of choking device the carburetor is equipped with; it is immaterial what type or kind of by-pass is used around the throttle valve; and it is immaterial what type or kind of means is used for increasing the supply of fuelwhen the choking device starts to move towards its closed position.

In the carburetor herein illustrated the th-rottling by-pass around the throttle valve is formed by two vertically-disposed ducts' provided in its exterior, adjacent its upper end, with an annular groove 32, and the top edge'of saidVenturi member is provided with one ormore notches 33. Normally, the Venturi member 9 occupiesthe position shown in Figure 2 of the drawings, in which position the annular groove 32 in the exterior of same is located at as point slightly above the arcshaped groove31,previously referred to, that Y forms the lower end of the by-pass around the throttlevalve. Ati/such times there is no communication between the by-pass ducts 29 and the portion of 'the main passageway 1 below the, .throttle valve, but there is communicatio'n between this portion of the main passagewayand the lfuel tube 10, which com.- munication isestablishedtby'an orifice 34 in the side' ofthe fuel tube 10 lthat registers with the annular groove 32 in the exterior of the Venturi member 9. Accordingly, when the throttle valve is closed, or only partly open,

and when the Venturi member 9 is in its raised or normal position, shown in Figure 2, some air will enter the fuel tube 10 from the portion of the main passageway 1 below the throttle valve by passing through the notches 33 downwardly into 'the annular groove 32 in the Venturi member 9, and thence into the fuel tube 10 through the orifice 34 in same, the

said air acting to reduce the suction that is exerted in the fuel tube 10 bv the intake of the engine.

When theVenturi member 9 that constitutes the choking device of the carburetor is moved downwardly towards its closed position, as shown in Figure 3, the annular groove 32 in the exterior of said member comes into registration with the arc-shaped groove 31, without, however, moving out of registration with the orifice 34 in the fuel supplying device 10, thereby causing the by-pass ducts 29 around thethrottle valve;

to become operative. As soon as said by-pass ducts 29 become operative, the high suction that exists in the intake of .the

engine is exerted on the orifice 34 in the side of the fuel tube 10, due of course, to the fact that-.said orifice registers with the annular groove 32 in the exterior of the Venturi member, which, at this time is in communication with the arc-shaped groove 31 from which the by-passducts 29 lead. Consequently, the suction on the idle speed fuel supplying Vdevice 14 will be increased, due to the fact that air ceases to flow into the fuel tube 10 through the orifice 34 in same. The result `is that an increased supply of fuel will be drawn upwardly through the fuel tube 10,

vary the idle speed of the engine withoutr changing the position of the throttle valve or the device that is `used to control the closed position ofthe throttle valve.

I, of course, realize that carburetors of con-l ventional design are equipped with choking devices that can be closed or set in a partly closed position, but I believe it is new to equip flow of fuel being supplied to the main. pasa carburetor with a choking device, which, when moved towards its-closed position, automatically brings into service a by-pass around the'throttle valve andl changes the volume of the 'medium owing through said by-pass according to the position of said choking device. I also believe it is new to construct a carburetor so that fuel will be supplied at a certain approximate rate at idle engine speeds when thechoking device 'of the carburetor is in its wide open positibn, but the act of moving said choking device towards its closed position automatically increases the rate of sageway of the carburetor.

Having thus described my invention, what v I claim as new and ,desire to secure byLetters Patent is:

, 11--A- carburetor provided with a main passa eway, a throttle -valve in said passageway, a nel supplying device leading from a source of supply of fuel and provided with a fuel discharge opening located in the edge of said throttle valve or admitting fuel to said main passageway above 'the throttle valve when said valve is closed or partly open, and means for adjusting said device so asto arrange the fuel discharge opening of same in operative relationship with the throttle valve. 1

Proximity to l 2.'- A carburetor provided with abody por- I tion that has a main passageway, a throttle valve in said passageway, a fuel supplying device mounted in said body portion at one side of said passageway Iand. provided with ,a fuel discharge opening arranged inproximity to the edge of the throttle valve foradmitting fuel to said passageway above the throttle valve when said valve is closed or rau . supplying device relatively to said body'portion toaccurately adjust the-fuel discharge bpening of same relatively to the throttle valve.

3. A carburetor provided with a body pori j tion that has a main passageway, a throttle valve in said passageway a fuel supplying del vicelmounted in said body portion at one side of said passageway and provided with a fuel discharge opening arranged in proximity to the edge of the throttle valve for admitting fuel to said passageway above the throttle valve when sald valve is closed or partly open,

and av rotatable member in the body portionv l of the carburetor provided with an eccentrically-disposed part that co-operateswith said fuel supplying device to shift said device .so as to adjust the fuel discharge opening of same relatively tothe throttle` valve.

4.` A carburetor provided with a body portion that has amain passageway, a throttle valve in saidfpassageway, a, fuel supplying device mounted in said bodyportion at one A t-l side ofsaid passageway and provided with a A fue] discharge openlng arranged in proximity to the edge of the throttle valve for admittingk fuel to said passageway above the throttle valve when said valve is closed or partly open, and an adjusting member for said supplying device l'rotatably mounted in the body p0rtion of the carburetor and provided with an eccentrically-disposed part that lits in a notch in the exterior of said device.

5. A carburetor provided witha main passageway, a throttle valve in said passageway, a Venturi member mounted in said passageway below said throttle valve and adapted to be adjusted lengthwise of said passageway to arrange it in different positions, a tubular element Whose' upper end-terminates inside of the inlet end of said Venturi member, a sta'-l tionary cup-shaped member surrounding said tubular element and arranged with its rim,

service.

in opposed relation to the lower end of said Venturi member so as to co-operate with the same to 'form an air inlet for said passageway, and a manually-operable means for moving said Venturi member relatively to said cupshaped member. Y

6. A carburetor provided with a main passageway, a throttle valve in said passageway, an idle speed fuel supplying device which supplies fuel when the throttle valve is in its closed or nearly closed position, a choking device for reducing the admission of air to said passageway, a by-pass around the throttle valve that is rendered operativeby the movement of said choking device towards its closed position, and means for automatically increasin the discharge of fuel from said idle spee .fuel supplying device when said by-pass comes into service.

7 A carburetor provided with a main passageway, a throttle valve in said passageway, a choking device for reducing the admission of air to said passageway, a device that supplies fuel at idle engine speeds, and means whereby the movement of said choking device towards its closed position automatically increases the discharge of fuel from said fuel supplying device and also increases the area of passageway through which the fuel is admitted to the intake of the engine at idle speeds. v

a choking member whose position i's a apted speed fuel supplying device, a by-pass around the throttle valve, separate and distinct from said idle speed fuel supplying device and adapted to be rendered operative by the movement of said choking member away from its normal open position, and means for causing the discharge of fuel from said idle speed fuel supplymg device to increase when said choking member is moved into its closed position and to diminish when said choking member is moved intoits open position.

9. A carburetor provided with a main .passageway, a throttle valve in said passageway..

a fuel duct leading from a supply of fuel for introducing fu'el into said main passageway above the throttle valve when said-valve is in its closed or nearly closed positiorna choking member arranged below the throttle valve for choking or reducing the admission of air to said main passageway, a by-pass around the throttle valve that is rendered operative by the movement of said choking member away from its normal open position and means for increasing the suction exerted on the source of supply from which said fuel duct leads when said by-pass comes into 10. A carburetor provided with a main y carburetor provided with a main passageway, a throttle valve in said passa eway,

way, a fuel duct leading from a supply of fuel for introducing fuel into said passageway above the throttlevalve when said `valve is in its closed or nearly closed position, a by-pass around the throttle valve, and a choking member reciprocatingly mounted in said main passageway below the throttle valve and arranged so that when it starts to move towards its closed position said by-pass will be rendered operative automatically and a greater suction exertedon the supply of fuel from which said fuel duct leads.

11. A carburetor provided with a main passageway, a throttle valve in said passageway, a fuel duct that leads from asupply of fuel for introducingfuelv into said passageway above the throttle valve when said valve is in its closed or nearly closed position,l aVenturi member reciprocatingly mounted in said passageway below the" throttle valve and adapted to be moved so as to chloke or reduce the admission of air to said passageway, a groove in the exterior of said Venturi member that is in communication with the portion of said passageway below the throttle valve, an orifice in said fuel duct that registers with `said groove in any position of said Venturi member, and a. by-pass around the throttle valve that is brought into communication with said groove as soon as said Ven- .turifmember starts to move away lfrom its normal open position.

12. A carburetor providedf with a main passageway, a throttle valve in said passageway, a movable Venturi member arranged in said passageway below` said throttle valve, a tubular member having is upper end positioned in the contracted portion of\said Venturi member, a substantially cup-shaped member surrounding said tubular member and arranged with its open end in opposed relation to the inlet end of said Venturi member so as to co-operate with same to` form an inlet opening -to said passageway, and

throttle setting, said second means compris-` ing a throttling by-pass around the throttle so arranged that when the choking device is moving towards its closed position said bypass will automatically come into service.

W'ILLIAM C. CARTER. 

